Add $o output for presin/preex2, explain what they do.
Add $o output for presin/preex2, explain what they do.

karolherbst/envytools,karolherbst/envytools,envytools/envytools,hakzsam/envytools,grate-driver/envytools,hakzsam/envytools,pierremoreau/envytools,envytools/envytools,grate-driver/envytools,grate-driver/envytools,pierremoreau/envytools,kfractal/envytools,hakzsam/envytools,karolherbst/envytools,MoochMcGee/envytools,pierremoreau/envytools,karolherbst/envytools,hakzsam/envytools,hakzsam/envytools,envytools/envytools,envytools/envytools,envytools/envytools,pierremoreau/envytools,karolherbst/envytools,grate-driver/envytools,MoochMcGee/envytools,pierremoreau/envytools,kfractal/envytools,kfractal/envytools,kfractal/envytools,MoochMcGee/envytools,MoochMcGee/envytools,MoochMcGee/envytools,kfractal/envytools,grate-driver/envytools